The present invention relates generally to lighting fixtures having one or more light-emitting devices, and more particularly to light-emitting devices having electrically insulated LED modules with respect to the main body of the lighting fixture and respective fasteners.
Light-emitting devices are known in the art in which an LED module including one or more LED chips is mounted on a substrate, the substrate being covered by a cover having a terminal board, and with power supplied from the terminal board to the LED module via the substrate. Such a conventional light-emitting device has a contact pattern arranged to allow electrical connection between the substrate and the terminal board. The contact pattern and the LED module are connected to each other by a wiring pattern or equivalent coupling. The substrate and the cover are fastened with screws to a metallic main body so as to allow contact and connection between the terminal board and the substrate, thereby improving ease of assembly.
However, soldering is generally applied in such devices to allow electrical connection between the LED module and the substrate. A solder crack may frequently occur in the substrate and/or the LED module caused by thermal shock. The substrate may be provided with a conductor foil spread close to an end surface of a screw hole when a conductive pattern is formed. If a metal screw is used, the electrical insulation properties between the substrate and the main body are easily deteriorated, including a dielectric breakdown under application of high voltage. If a screw is alternatively made of resin, the screw itself may deteriorate due to secular changes and stresses caused by thermal deformation, further resulting in low reliability in terms of strength.